Social media has allowed the public to enjoy fashion in real time. Brands too have reaped the benefits of this: expanding their reach through Instagram livestreams, posting behind-the-scenes images, and providing more intimate access to designers and their creative process. But, as luxury houses have surely realized over the past few seasons, letting the public into the previously private world of fashion also means opening the door to public callouts.

In May, a balloon-sleeved Gucci jacket from the brand's heavily Instagrammed cruise 18 show sparked debates over the difference between homage and plagiarism. Some believed Gucci had knocked off a knock-off — citing the piece's similarity to a handmade creation of Harlem designer Dapper Dan, who riffed on Gucci designs in the 80s. The moment perfectly embodied a major problem in the industry: designers' obsession with repurposing the old into something new.

That's what makes the account @dietprada a delight for fashion nerds. It's a collection of all those "I think I've seen this before…" runway moments, pairing familiar-looking pieces with their alleged inspirations. The account was not born out of ill-intent, however. The anonymous creator of @dietprada works in the fashion industry, and the account is simply a natural extension of their obsession: studying fashion history to understand how the trends of today come from the past. They hope to shift from Instagram to visual essays soon. "It'll be really great for talking out my ideas," they explain to i-D. Below, they discuss the demands — and career risks — of running a secret Instagram account and what makes fashion so rife with appropriation and plagiarism.

How did the account first come about?We officially made an Instagram account two years ago — I used to run it with one of my friends, but now it's just me. We would sit and scroll through what used to be Style.com and click through the runway shows. We would crack ourselves up and be like, "That's so 2000s Galliano, what were they thinking!" It got to the point where we were collaging them together to show each other and we were like, "We need to put this on the internet."

What's behind your in-depth knowledge of fashion?I've been in the industry for almost eight years now. And my degree is in fashion — so if you add that, it like 12 years. I was lucky enough to have access to all the runway shows online. So just looking at things obsessively over the years has let me build up this encyclopedic knowledge. Even just going back sometimes and reading Diana Vreeland's books. History is important, you have to know where everything came from.

Do you feel like giving credit to the past is an underappreciated art? Sometimes it feels like we're too concerned with what appears to be "new."That's what I've been really trying to focus on the last couple of months: how quickly things are getting knocked off. Because it's like I don't care if someone copies a Balenciaga jacket from the 50s. It's like, so what? That's fair game. But when you copy Balenciaga's men's suits from last season… There's just this trend, trend, trend thing that's making everything really homogenous.

So for you there's a distinction between inspiration and plagiarism?I think you can look at an old vintage garment and draw inspiration from that. But sometimes the thinking is more XYZ sells, so if I copy them I know my stuff will sell too. They're like, "I wanna make money, so I'm gonna copy it," instead of, "Oh, this is good design so I'm gonna copy it."

In your opinion, what designers and brands are good at reinterpreting designs from the past?J.W.Anderson. Some people are hitting me up like, "Oh, he copied the whole Saint Laurent heart print!" and I'm like: "One, they didn't invent hearts and two, it's such a new way and you can see that [design] is going to be our new wave so… who cares." Because even if it's copying, he's copying in an original way (if that makes sense). There's nothing new left in this world, it's just all about how you are using it. Also, I think there are some really cool new things coming out of New York right now, like Landlord.

What is it about fashion specifically that leads to so many copycat moments?I think because fashion is so visual and on a schedule the waves of copying are really noticeable. I feel like restaurants and other stuff get knocked off all the time, but it's not like, "The restaurants for spring/summer 18 are poke!" It's more gradual. It's just the way the commercial and the visual coincides in fashion that makes things so ripe for copying.

How often do you find that race and culture fit into these copycat moments?Cultural appropriation is always going to be huge in fashion, but the black and street culture stuff is getting so derived right now. And it's weird. Because it's coming from these brands that are in Belgium and France — where their culture is not like that… at all. If a brand from New York does streetwear, I can at least be like yeah, okay, we invented it, so it makes sense for it to come out of here.

Which iconic designer is referenced and borrowed from the most, do you think?Prada, constantly. There's so much variety in her archive that something can just look like it's a Prada garment by sheer accident because she has so much scope. But you know when somebody's doing her tropes. Like "girlishness," or "innerwear as outerwear" bra stylings, or the way she uses things like color, feathers, and rhinestones. You go, "Oh, that's so Prada!"

What about the newer faces in the fashion world? Who is creating a new vision that's getting borrowed from a lot?The Balenciaga and Vetements thing is so huge. Which is funny, because their stuff is drawing on Margiela from the 90s. But I think the fact that Margiela played around with regular clothing so much is why we're seeing him get borrowed from a lot more than, say, Comme Des Garçons. But, it's also like Comme is so much about large architectural and sculptural shapes, so how are you going to reference that without it being obvious?